Field of the Invention
The invention relates to a method for suppressing vibration in the drive train of a motor vehicle, in which the rpm of the vehicle engine is detected, the rpm gradient is derived from the rpm and evaluated, and if impermissible vibration is detected, the torque of the engine is reduced by varying the ignition angle, wherein the torque reduction is controlled as a function of an upper and a lower limit value for the rpm gradient.
A method which is known from German Published, Non-Prosecuted Application DE 40 09 791 A1 is used to suppress vibrations in the drive train of a motor vehicle having an engine rpm which is detected by a sensor.
When vibration occurs in the drive train, a correcting variable ascertained in a correcting device is delivered to the engine and reduces the engine torque by varying the instant of ignition. The instant of ignition is varied, for instance, by switching over from a first ignition performance graph to a second one in an ignition control unit.
Vibration in the drive train of a motor vehicle, which is caused by a load change in the drive and by road surface factors while driving, is rpm-dependent. The vibration, which can also be called bucking, can above all occur at an abrupt transition from low partial load to full load in the rpm range, in other words above all during the startup process.